Etching apparatus



Sept. 27, 1955 NEUHAUS 2,718,723

' ETCHING APPARATUS Filed July 9, 1953 4 Sheets-Sheet 3 Fritz AI h by:

Sept. 27, 1955 F. NEUHAUS 2,718,723

ETCHING APPARATUS 7 Filed July 9, 1953 4 Sheets-Sheet 4 Fig. ,5

Fr ,1? A/mhaus fl/wdmd 5. 577147122 United States Patent ETCHING APPARATUS Fritz Neuhaus, Trimbach, near Olten, Switzerland Application July 9, 1953, Serial No. 367,011

Claims priority, application Germany July 12, 1952 Claims. (Cl. 41-9) The present invention relates to an apparatus for etching printing plates, galvanos, or the like.

In the art of printing, and especially in intaglio printing, the design to be duplicated is generally etched into a printing plat or the like. Those places of the plate or block which are to remain free of ink are then suitably masked so as not to be affected by the acid or lye. Such etching of the printing plate, which, is preferably slightly inclined, is sprayed as evenly as possible with an etching fluid. For this purpose, either a rotating device which sprays up the etching fluid by purely mechanical means or a pump is used which sprays the fluid under pressure through a nozzle upon the printing plate.

These known devices are, however, impractical because they contain movable parts which must always be in contact with the etching fluid and therefore soon corrode. Also, the spraying done with such apparatus is not as uniform as desirable nor can it be regulated with sufficient accuracy.

It is therefore the object of the present invention to devise a novel etching apparatus which avoids all of the deficiencies mentioned above and also obtains the additional advantages of a simplified construction and increased efficiency of operation. This apparatus according to the invention utilizes pneumatic means for spraying the etching fluid upon the printing plate, and preferably uses compressed air to act upon the etching fluid below or at the surface thereof. Thus, no movable parts are required for an effective spraying operation but only a simple nozzledevice which lies in the etching fluid, and through which compressed air is fed through upwardly directed openings therein.

A further object of the present invention is to devise a very simple control mechanism for regulating the spraying operation. Such control may consist of means for changing the pressure or the amount of air supplied to the spraying nozzle and for varying the depth to which the spraying nozzle is immersed within the etching fluid.

One of-the features of the invention is the particular manner of always maintaining a uniform spraying action independently of the amount of fluid supplied.

. Another feature of the invention is the novel design of a spraying device in the form of a nozzle tube and the particular arrangement and construction of the spraying or nozzle openings in such tube.

Still another feature of the invention is the construction of'the entire novel mechanism so as to form a single unit which can be placed in its entirety into any kind of etching apparatus or vessel without requiring any special installation thereof. Such easy removability of the spraying mechanism also facilitates proper cleaning thereof.

Further objects, features, and advantages of the present invention Will be apparent from the following description thereof and the accompanying drawings, in which:

Fig. 1 is a top view of an apparatus for etching printing plates or the like by means of the novel pneumatic method;

2,718,723 Patented Sept. 27, 1955 Fig. 2 is a vertical longitudinal section taken along the line II--II of Fig. 1;

Fig. 3 is a vertical cross section taken along line IIIIII of Fig. 1, but differing therefrom in that the etching fluid may also be sprayed toward both longitudinal sides of the apparatus;

Fig. 4 is a horizontal section similar to but slightly enlarged relative to that shown in Fig. 3 and differing therefrom only by the particular arrangement of the float centration. As shown in Fig. 1, one side Wall 3 of the tank 1 is slightly outwardly inclined or it may consist of a separate piece which may be hooked on to the upper edge of the tank 1 by inner overlapping extensions 4 and outer supporting members 5. A similar wall 3 may also be provided on the opposite side of the tank 1, as shown in Fig. 3. This wall 3 or 3' serves as a support for the printing plates 6 or the like shown in various sizes ready to be etched and held thereon by means of brackets 7. If desired, two such brackets 7 may be provided on each wall to hold two rows of printing plates thereon one above.

the other.

It is the object of the invention to spray the printing plates, galvanos, or the like 6 uniformly with the etching fluid 2 stored in the tank 1, and to do this in such a manner that an adequate amount of fluid is sprayed upon every one of the plates on the wall or walls 3, 3. The etching fluid then flows downwardly along these walls and back into the tank 1, so that the unmasked surface parts of the printing plates are etched to an extent depending upon the length of time during which they are exposed to the action of the etching fluid. The continuously sprayed etching fluid also automatically washes down any salts which are formed by the etching process, thus producing a more cleanly and uniformly etched plate.

For spraying the fluid upwardly and upon the plates 6,

a current of compressed air is used which is supplied from 10 at a force depending upon the pressure thereof. Since the openings of the nozzles 10 are located slightly below the surface of the fluid, as shown in Fig. 3, the various jets take along or blow the fluid 2 upwardly and upon the printing plates 6. If two supporting walls 3 are provided, as shown in Fig. 3, the tube 9 preferably has nozzle openings 10 inclined in both directions so as to spray the fluid simultaneously upon both walls.

For automatically positioning the nozzle tube 9 at the proper distance below the surface of the etching fluid in the tank 1, the invention provides a float mechanism consisting of two floats 11 and 12 located at opposite sides of the tube 9 and each preferably consisting of three hollow tubes. These tubular floats 11 and 12 are connected by brackets 13, 14, and 15 which also support of each screw. .The threaded part of screws 16 engage with brackets 13, 14, and 15, respectively, so that by turning them the position of the nozzle tube 9 may be adjusted in a vertical direction relative to the floats carried there y- Since the floats 11 and 12 automatically adjust them selves to the raising or lowering surface of the fluid, the nozzle tube 9 also carries out such movement. However, by turning the screws 16, this tube may also be adjusted in a vertical direction so that the nozzle openings may be raised or lowered relative to the fluid surface. Lowering of the nozzle tube 9 without change of air pressure then results in a bigger spray, while raising of the nozzle tube 9 produces a finer spray. Normally, the nozzle tube is preferably adjusted so that the mouth of the nozzle openings 10 lies approximately 0.08 inch below the fluid surface, whereas the air pressure is adjusted to 2. to 3 atmospheres.

In order to ensure that the float mechanism freely follows the variations of the fluid surface but is protected from swinging or shifting laterally, each of the narrow side walls of the tank 1 is provided with a vertical bracket or 21 fitting into a slot 22 or 23 in a transverse bracket 24 or 25 connecting the float tubes 11 and 12 at their ends to one another. Each of the slots 22 and 23 carries a vertical lining 26 for increasing the vertical bearing surface to prevent the float mechanism from swinging laterally or even remaining in an angular position. The nozzle openings 10 may be of a cylindrical shape or, as shown in Fig. 4, they may be slightly conical toward the outside so as to distribute or spread the individual air jets more evenly which prevents the air from shooting through the etching fluid and instead carries it along to form a proper spray.

The brackets 7 for holding the printing plates 6 are suitably shaped so as to form gutters for passing off the etching fluid which has been sprayed thereon. For this purpose, these brackets or gutters 7 may either have an outlet or drain on their end or they may be perforated at their lower sides. Also, the wall surfaces 3 and 3' may be provided with suitable means, such as indentations, projections, or grooves, to reduce the area or points of contact of the printing plates thereon so that any etching fluid which has been sprayed above the plates can freely run down behind them. Furthermore, the lower bracket 7 may carry a screening wall 27 extending downwardly to a point near the bottom of the tank 1, as shown in dotted lines in Fig. 3, for preventing the drained-off fluid which has been contaminated by the etching process from coming into immediate contact with the fresh fluid in the tank. Thus, the impurities can settle on the bottom of the tank behind the screening wall 27 Without contaminating the etching fluid.

Fig. 5 illustrates an etching apparatus according to the present invention in which all four sides are utilized for spraying the etching fluid thereon. The nozzle tube 9' t of this modified construction is bent into a rectangular shape so as to conform with the rectangular shape of the tank 1. The air pressure conduit 8 again comes from above, while all the nozzle openings 10 in this case are outwardly inclined. The float mechanism 11 is likewise of rectangular shape and surrounds the nozzle tube 9'. In order to increase its buoyancy, the mechanism may also be provided at the middle thereof with an additional float tube or series of such tubes 12. The nozzletube 9' may be supported in the same manner as described above and shown in Fig. 4 by screws 16 which permit an adjustment of the tube in vertical direction. The vertical bearing of the float mechanism by elements 20, 21, 24, and 25 may also be of a construction as previously described.

The entire apparatus as described for spraying the etching fluid may consist of a separate unit which may be immersed into or removed from the tank 1. Such removabili y facilitates th clean ng of the entire apparatus s well as of the tank 1. The apparatus preferably consists of an acid and lye resistant plastic or similar material and can therefore be made very cheaply and of very little weight.

Various other modifications and improvements may suitably be made without departing from the scope of the present invention, as defined in the following claims.

I claim:

1. In an etching apparatus, in combination, a container adapted to receive a liquid; conduit means for introducing a fluid under pressure below the surface of the liquid within said container, said conduit means being arranged within said container and having at least one upwardly directed opening so that when fluid under pressure is introduced into said conduit means the fluid will flow through said opening whereby liquid within said container will be carred along by the fluid under pressure and be ejected above the surface of the liquid; and float means adapted to float on the liquid and operatively associated with said conduit means for maintaining said conduit means at a predetermined distance below the surface of the liquid within said container.

2. In an etching apparatus, in combination, a container adapted to receive a liquid; conduit means for introducing a fluid under pressure below the surface of the liquid within said container, said conduit means including a tubular member arranged within said container and having at least one upwardly directed opening so that when fluid under pressure is introduced into said conduit means the fluid will flow through said opening of said tubular member whereby liquid within said container will be carried along by the fluid under pressure and be ejected above the surface of the liquid; and float means adapted to float on the liquid and operatively associated with said tubular member for maintaining said tubular member at a predetermined distance below the surface of the liquid within said container.

3. In an etching apparatus, in combination, a container adapted to receive a liquid; conduit means for introducing a fluid under pressure below the surface of the liquid within said container, said conduit means including a tubular member arranged within said container and having a plurality of upwardly directed openings so that s when fluid under pressure is introduced into said con duit means the fluid will flow through said openings of said tubular member whereby liquid within said container will be carried along by the fluid under pres sure and be ejected above the surface of the liquids; and float means adapted to float on the liquid and opera tively associated with said tubular member for maintaining said tubular member at a predetermined distance below the surface of the liquid within said container.

4. In an etching apparatus, in combination, a container adapted to receive a liquid; conduit means for introducing a fluid under pressure below the surface of the liquid within said container, said conduit means including a tubular member arranged within said container and having a plurality of upwardly directed openings, said openings emanating radially from said tubular member, so that when fluid under pressure is introduced into said conduit means the fluid will flow through said openings of said tubular member whereby liquid within said container will be carried along by the fluid under pressure and be ejected above the surface of the liquid; and float means adapted to float on the liquid and operatively associated with said tubular member for maintaining said tubular member at a predetermined distance below the surface of the liquid within said container.

5. In an etching apparatus, in combination, a container adapted to receive a liquid; conduit means for introducing a fluid under pressure below the surface of the liquid within Said container, said conduit means including a tubular member arranged within said container and. having a, plurality of upwardly directed openings, said openings emana ing radially from said tubular member, he axes of said openings lying in at least two planes, so that when fluid under pressure is introduced into said conduit means the fluid will flow through said openings of said tubular member whereby liquid within said container will be carried along by the fluid under pressure and be ejected above the surface of the liquid; and float means adapted to float on the liquid and operatively associated with said tubular member for maintaining said tubular memher at a predetermined distance below the surface of the liquid within said container.

6. In an etching apparatus, in combination, a container adapted to receive a liquid; conduit means for introducing a fluid under pressure below the surface of the liquid within said container, said conduit means being arranged Within said container and having at least one upwardly directed opening so that when fluid under pressure is introduced into said conduit means the fluid will flow through said opening whereby liquid within said con tainer will be carried along by the fluid under pressure and be ejected above the surface of the liquid; float means adapted to float on the liquid and operatively associated withsaid conduit means for maintaining said conduit means at a predetermined distance below the surface of the liquid within said container; and adjusting means operatively associated with said conduit means and said float means for varying said predetermined distance.

7. ,In an etching apparatus, in combination, a container adapted to receive a liquidg-conduit means for introducing a fluid under pressure below the surface of the liquid within said container, said conduit means being arranged within said container and having at least one upwardly directed opening so that when fluid under pressure is introduced into said conduit means the fluid will flow through said opening whereby liquid within said container will be carried along by the fluid under pressure and be ejected above the surface of the liquid; float means including at least one Support bracket and at least one float member fixedly mounted to said support bracket, said float member being adapted to float on the liquid, said float means being operatively associated with said conduit means for maintaining said conduit means at a predetermined distance below the surface of the liquid within said container; and adjusting means operatively associated with said conduit means and said support bracket of said float means for varying said predetermined distance.

8. In an etching apparatus, in combination, a container adapted to receive a liquid; conduit means for introducing a fluid under pressure below the surface of the liquid within said container, said conduit means including a tubular member arranged within said container and having at least one upwardly directed opening so that when fluid under pressure is introduced into said conduit means the fluid will flow through said opening whereby liquid within said container will be carried along by the fluid under pressure and be ejected above the surface of the liquir, said tubular member also having at least one projecting member fixedly mounted thereto; float means including at least one support bracket and at least one float member fixedly mounted to said support bracket, said float member being adapted to float on the liquid, said float means being operatively associated with said tubular member for maintaining said tubular member at a predetermined distance below the surface of the liquid within said container; and adjusting means operatively associated with said projecting member of said tubular member and said support bracket of said float means for varying said predetermined distance.

9. In an etching apparatus, in combination, a container adapted to receive a liquid; conduit means for introducing a fluid under pressure below the surface of the liquid within said container, said conduit means ineluding a tubular member arranged within said container and having at least one upwardly directed opening so that when fluid under pressure is introduced into said conduit means the fluid will flow through said opening whereby liquid within said container will be carried along by the fluid under pressure and be ejected above the surface of the liquid, said tubular member also having at least one projecting member fixedly mounted thereto; float means including at least one support bracket and at least one float member fixedly mounted to said support bracket, said float member being adapted to float on the liquid, said float means being operatively associated with said tubular member for maintaining said tubular member at a predetermined distance below the surface of the liquid within said container; and adjusting means engaging said projecting member of said tubular member and threadedly engaging said support bracket of said float means for varying said predetermined distance.

10. In an etching apparatus, in combination, a container adapted to receive a liquid; conduit means for introducing a fluid under pressure below the surface of the liquid within said container, said conduit means being arranged within said container and having at least one upwardly directed opening so that when fluid under pressure is introduced into said conduit means the fluid will flow through said opening whereby liquid within said con tainer will be carried along by the fluid under pressure and be ejected above the surface of the liquid; float means adapted to float on the liquid and operatively associated with said conduit means for maintaining said conduit means at apredetermined distance below the surface of the liquid within said container; and guide means operatively associated with said conduit means for limiting movement thereof to movement within a substantially vertical plane.

11. In an etching apparatus, in combination, a container adapted to receive a liquid; conduit means for introducing a fluid under pressure below the surface of the liquid within said container, said conduit means being arranged Within said container and having at least one upwardly directed opening so that when fluid under pressure is introduced into said conduit means the fluid will flow through said opening whereby liquid within said container will be carried along by the fluid under pressure and be ejected above the surface of the liquid; float means adapted to float on the liquid and operatively associated with said conduit means for maintaining said conduit means at a predetermined distance below the surface of the liquid within said container; and guide brackets fixedly mounted to said container and adapted to be engaged by said float means whereby movement of said float means and said conduit means is limited to movement within a substantially vertical plane.

12. In a spraying apparatus, in combination, a con tainer adapted to receive a liquid to be sprayed; conduit means for introducing a fluid under pressure below the surface of the liquid within said container, said conduit means being arranged within said container and having a plurality of upwardly directed openings so thatwhen fluid under pressure is introduced into said conduit means the fluid will flow through said openings whereby liquid within said container will be carried along by the fluid under pressure and be ejected above the surface of the liquid, the axes of said openings being directed in a plurality of directions so that liquid ejected above the surface of the liquid will be ejected in a plurality of directions; and float means adapted to float on the liquid and operatively associated with said conduit means for maintaining said conduit means at a predetermined distance below the surface of the liquid within said container.

13. In a spraying apparatus, in combination, a container adapted to receive a liquid to be sprayed; conduit means for introducing a fluid under pressure below the surface of the liquid within said container, said conduit means being arranged within said container and having a plurality of upwardly directed openings so that when fluid under pressure is introduced into said conduit means the fluid will flow through said openings whereby liquid within said container will be carried along by the fluid under pressure and be ejected above the surface of the liquid, the axes of said openings being directed in at least four directions so that liquid ejected above the surface of the liquid will be ejected in at least four directions; and float means adapted to float on the liquid and operatively associated with said conduit means for maintaining said conduit means at a predetermined distance below the surface of the liquid within said container.

14. In an etching apparatus, in combination, a container adapted to receive a liquid, said container having an endless inner wall face; conduit means for introducing a fluid under pressure below the surface of the liquid within said container, said conduit means including a tubular member arranged'within said container and having a plurality of upwardly directed openings so that when fluid under pressure is introduced into said conduit means the fluid will flow through said openings whereby liquid within said container will be carried along by the fluid under pressure and be ejected above the surface of the liquid, the axis of said tubular member being substantially parallel to said endless inner wall face of said container; and float means adapted to float on the liquid and operatively associated with said tubular member for maintaining said tubular member at a predetermined distance below the surface of the liquid within said container adapted to receive a liquid, said container having two pairs of parallel opposite side walls, one pair of said side walls being perpendicular to the other pair of said side walls; conduit means for introducing a fluid under pressure below the surface of the liquid within said container, said conduit means including a tubular member arranged within said container and having a plurality of upwardly directed openings so that when fluid under pressure is introduced into said conduit means the fluid will flow through said openings whereby liquid Within said container will be carried along by the fluid under pressure and be ejected above the surface of the liquid, said tubular member including two pairs of parallel sections, one pair of said sections being perpendicular to the other pair of said section, said sections being arranged within said container so that the axis of each of said sections is parallel to and spaced a predetermined distance from one of said side walls; and float means adapted to float on the liquid and operatively associated with said tubular member for maintaining said tubular member at a predetermined distance below the surface of the liquid within said container.

References Cited in the file of this patent UNITED STATES PATENTS 627,430 Levy June 20, 1889 

